A processor may have an associated instruction set that includes instructions that the processor is capable of executing. In some cases, the instruction set may include variable length instructions, e.g., at least one of the instructions may have a length that is different from another instruction in the instruction set. To illustrate, at least some of the instructions in the instruction set may include instructions that are executable by a previous generation of the processor, to enable backward compatibility with the previous generation processor. Determining a length of each instruction may consume time (e.g., processor cycles), power, or both.